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<a href="drop__timer_8hpp.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a id="l00001" name="l00001"></a><span class="lineno">    1</span><span class="comment">/* Flow</span></div>
<div class="line"><a id="l00002" name="l00002"></a><span class="lineno">    2</span><span class="comment"> * Copyright 2023 Akamai Technologies, Inc.</span></div>
<div class="line"><a id="l00003" name="l00003"></a><span class="lineno">    3</span><span class="comment"> *</span></div>
<div class="line"><a id="l00004" name="l00004"></a><span class="lineno">    4</span><span class="comment"> * Licensed under the Apache License, Version 2.0 (the</span></div>
<div class="line"><a id="l00005" name="l00005"></a><span class="lineno">    5</span><span class="comment"> * &quot;License&quot;); you may not use this file except in</span></div>
<div class="line"><a id="l00006" name="l00006"></a><span class="lineno">    6</span><span class="comment"> * compliance with the License.  You may obtain a copy</span></div>
<div class="line"><a id="l00007" name="l00007"></a><span class="lineno">    7</span><span class="comment"> * of the License at</span></div>
<div class="line"><a id="l00008" name="l00008"></a><span class="lineno">    8</span><span class="comment"> *</span></div>
<div class="line"><a id="l00009" name="l00009"></a><span class="lineno">    9</span><span class="comment"> *   https://www.apache.org/licenses/LICENSE-2.0</span></div>
<div class="line"><a id="l00010" name="l00010"></a><span class="lineno">   10</span><span class="comment"> *</span></div>
<div class="line"><a id="l00011" name="l00011"></a><span class="lineno">   11</span><span class="comment"> * Unless required by applicable law or agreed to in</span></div>
<div class="line"><a id="l00012" name="l00012"></a><span class="lineno">   12</span><span class="comment"> * writing, software distributed under the License is</span></div>
<div class="line"><a id="l00013" name="l00013"></a><span class="lineno">   13</span><span class="comment"> * distributed on an &quot;AS IS&quot; BASIS, WITHOUT WARRANTIES OR</span></div>
<div class="line"><a id="l00014" name="l00014"></a><span class="lineno">   14</span><span class="comment"> * CONDITIONS OF ANY KIND, either express or implied.</span></div>
<div class="line"><a id="l00015" name="l00015"></a><span class="lineno">   15</span><span class="comment"> * See the License for the specific language governing</span></div>
<div class="line"><a id="l00016" name="l00016"></a><span class="lineno">   16</span><span class="comment"> * permissions and limitations under the License. */</span></div>
<div class="line"><a id="l00017" name="l00017"></a><span class="lineno">   17</span><span class="comment"></span> </div>
<div class="line"><a id="l00018" name="l00018"></a><span class="lineno">   18</span><span class="comment">/// @file</span></div>
<div class="line"><a id="l00019" name="l00019"></a><span class="lineno">   19</span><span class="comment"></span><span class="preprocessor">#pragma once</span></div>
<div class="line"><a id="l00020" name="l00020"></a><span class="lineno">   20</span> </div>
<div class="line"><a id="l00021" name="l00021"></a><span class="lineno">   21</span><span class="preprocessor">#include &quot;<a class="code" href="detail_2net__flow__fwd_8hpp.html">flow/net_flow/detail/net_flow_fwd.hpp</a>&quot;</span></div>
<div class="line"><a id="l00022" name="l00022"></a><span class="lineno">   22</span><span class="preprocessor">#include &quot;<a class="code" href="peer__socket_8hpp.html">flow/net_flow/peer_socket.hpp</a>&quot;</span></div>
<div class="line"><a id="l00023" name="l00023"></a><span class="lineno">   23</span><span class="preprocessor">#include &quot;<a class="code" href="shared__ptr__alias__holder_8hpp.html">flow/util/shared_ptr_alias_holder.hpp</a>&quot;</span></div>
<div class="line"><a id="l00024" name="l00024"></a><span class="lineno">   24</span><span class="preprocessor">#include &lt;boost/enable_shared_from_this.hpp&gt;</span></div>
<div class="line"><a id="l00025" name="l00025"></a><span class="lineno">   25</span><span class="preprocessor">#include &lt;set&gt;</span></div>
<div class="line"><a id="l00026" name="l00026"></a><span class="lineno">   26</span> </div>
<div class="line"><a id="l00027" name="l00027"></a><span class="lineno">   27</span><span class="keyword">namespace </span><a class="code hl_namespace" href="namespaceflow_1_1net__flow.html">flow::net_flow</a></div>
<div class="line"><a id="l00028" name="l00028"></a><span class="lineno">   28</span>{</div>
<div class="line"><a id="l00029" name="l00029"></a><span class="lineno">   29</span><span class="comment">// Types.</span></div>
<div class="line"><a id="l00030" name="l00030"></a><span class="lineno">   30</span><span class="comment"></span> </div>
<div class="line"><a id="l00031" name="l00031"></a><span class="lineno">   31</span><span class="comment">/**</span></div>
<div class="line"><a id="l00032" name="l00032"></a><span class="lineno">   32</span><span class="comment"> * Internal `net_flow` class that maintains the Drop Timer for DATA packet(s) to have been sent out</span></div>
<div class="line"><a id="l00033" name="l00033"></a><span class="lineno">   33</span><span class="comment"> * over a connection but not yet acknowledged by the receiver.  This is similar to the</span></div>
<div class="line"><a id="l00034" name="l00034"></a><span class="lineno">   34</span><span class="comment"> * Retransmission Timer of TCP (although the way that timer works is not solidly standardized,</span></div>
<div class="line"><a id="l00035" name="l00035"></a><span class="lineno">   35</span><span class="comment"> * though there are recommended setups in RFCs like RFC 6298).  However, this applies even with</span></div>
<div class="line"><a id="l00036" name="l00036"></a><span class="lineno">   36</span><span class="comment"> * retransmission disabled (which is allowed in NetFlow but not in TCP), so it would be incorrect to</span></div>
<div class="line"><a id="l00037" name="l00037"></a><span class="lineno">   37</span><span class="comment"> * call it `Rexmit_timer`; on the other hand when retransmission is enabled, Drop_timer will still be</span></div>
<div class="line"><a id="l00038" name="l00038"></a><span class="lineno">   38</span><span class="comment"> * an accurate name (as a packet has to be considered Dropped before we retransmit it).  `net_flow`</span></div>
<div class="line"><a id="l00039" name="l00039"></a><span class="lineno">   39</span><span class="comment"> * users should not use this class directly.</span></div>
<div class="line"><a id="l00040" name="l00040"></a><span class="lineno">   40</span><span class="comment"> *</span></div>
<div class="line"><a id="l00041" name="l00041"></a><span class="lineno">   41</span><span class="comment"> * The basic idea is: if you send a packet, and it&#39;s not acknowledged within some amount of time,</span></div>
<div class="line"><a id="l00042" name="l00042"></a><span class="lineno">   42</span><span class="comment"> * then consider that packet Dropped.  (At that point you can take it out of the In-flight window,</span></div>
<div class="line"><a id="l00043" name="l00043"></a><span class="lineno">   43</span><span class="comment"> * or retransmit it, or whatever else is appropriate.)  Beyond this concept the details are</span></div>
<div class="line"><a id="l00044" name="l00044"></a><span class="lineno">   44</span><span class="comment"> * ambiguous, and there is no one right/standard/accepted answer for how it should work. For</span></div>
<div class="line"><a id="l00045" name="l00045"></a><span class="lineno">   45</span><span class="comment"> * example, when to restart the timer?  What to do with the timer after it fires?  Etc.  Therefore</span></div>
<div class="line"><a id="l00046" name="l00046"></a><span class="lineno">   46</span><span class="comment"> * the class is reasonably configurable, so that we can experiment with different approaches.</span></div>
<div class="line"><a id="l00047" name="l00047"></a><span class="lineno">   47</span><span class="comment"> *</span></div>
<div class="line"><a id="l00048" name="l00048"></a><span class="lineno">   48</span><span class="comment"> * This class works together with Node, Peer_socket, and Server_socket and accordingly assumes</span></div>
<div class="line"><a id="l00049" name="l00049"></a><span class="lineno">   49</span><span class="comment"> * very specific algorithms are used in sending and handling acknowledgments.  However it</span></div>
<div class="line"><a id="l00050" name="l00050"></a><span class="lineno">   50</span><span class="comment"> * could pretty easily be swapped out with another implementationr</span></div>
<div class="line"><a id="l00051" name="l00051"></a><span class="lineno">   51</span><span class="comment"> *</span></div>
<div class="line"><a id="l00052" name="l00052"></a><span class="lineno">   52</span><span class="comment"> * A Drop_timer works as follows.  It keeps an internal timer that fires every DTO seconds, where</span></div>
<div class="line"><a id="l00053" name="l00053"></a><span class="lineno">   53</span><span class="comment"> * DTO is computed externally (from SRTT, etc.).  Certain events start or restart the timer (e.g.,</span></div>
<div class="line"><a id="l00054" name="l00054"></a><span class="lineno">   54</span><span class="comment"> * receiving an acknowledgment).  Other events stop the timer (namely having no more In-flight</span></div>
<div class="line"><a id="l00055" name="l00055"></a><span class="lineno">   55</span><span class="comment"> * packets).  Then when the timer fires, certain actions have to be taken, such as considering</span></div>
<div class="line"><a id="l00056" name="l00056"></a><span class="lineno">   56</span><span class="comment"> * packets Dropped and/or restarting the timer.  Additionally the DTO value itself can be written to</span></div>
<div class="line"><a id="l00057" name="l00057"></a><span class="lineno">   57</span><span class="comment"> * by Drop_timer (e.g., timer backoff).</span></div>
<div class="line"><a id="l00058" name="l00058"></a><span class="lineno">   58</span><span class="comment"> *</span></div>
<div class="line"><a id="l00059" name="l00059"></a><span class="lineno">   59</span><span class="comment"> * Therefore, the interface of Drop_timer is simple: you call `on_...()`, when a Drop</span></div>
<div class="line"><a id="l00060" name="l00060"></a><span class="lineno">   60</span><span class="comment"> * Timer-influencing event has occurred; and when some action needs to be taken due to a Drop Timer</span></div>
<div class="line"><a id="l00061" name="l00061"></a><span class="lineno">   61</span><span class="comment"> * firing, it calls a user-supplied callback which will perform that action.  The action callbacks</span></div>
<div class="line"><a id="l00062" name="l00062"></a><span class="lineno">   62</span><span class="comment"> * are supplied at construction.  Drop_timer internally takes care of everything in-between:</span></div>
<div class="line"><a id="l00063" name="l00063"></a><span class="lineno">   63</span><span class="comment"> * running/stopping the timer, catching the timer firing, etc.  All of the &quot;policy&quot; about how the</span></div>
<div class="line"><a id="l00064" name="l00064"></a><span class="lineno">   64</span><span class="comment"> * timer operates is also inside.  Calling done() means the socket is done, and no action callbacks</span></div>
<div class="line"><a id="l00065" name="l00065"></a><span class="lineno">   65</span><span class="comment"> * will subsequently fire.</span></div>
<div class="line"><a id="l00066" name="l00066"></a><span class="lineno">   66</span><span class="comment"> *</span></div>
<div class="line"><a id="l00067" name="l00067"></a><span class="lineno">   67</span><span class="comment"> * To schedule the timer, Drop_timer shares Node&#39;s main event queue (Node::m_task_engine).</span></div>
<div class="line"><a id="l00068" name="l00068"></a><span class="lineno">   68</span><span class="comment"> *</span></div>
<div class="line"><a id="l00069" name="l00069"></a><span class="lineno">   69</span><span class="comment"> * ### Thread safety ###</span></div>
<div class="line"><a id="l00070" name="l00070"></a><span class="lineno">   70</span><span class="comment"> * To be used in the containing Node&#39;s thread W only.</span></div>
<div class="line"><a id="l00071" name="l00071"></a><span class="lineno">   71</span><span class="comment"> *</span></div>
<div class="line"><a id="l00072" name="l00072"></a><span class="lineno">   72</span><span class="comment"> * Implementation notes</span></div>
<div class="line"><a id="l00073" name="l00073"></a><span class="lineno">   73</span><span class="comment"> * --------------------</span></div>
<div class="line"><a id="l00074" name="l00074"></a><span class="lineno">   74</span><span class="comment"> *</span></div>
<div class="line"><a id="l00075" name="l00075"></a><span class="lineno">   75</span><span class="comment"> * Having written this class, it looks over-engineered.  The code would be shorter (no `shared_ptr`,</span></div>
<div class="line"><a id="l00076" name="l00076"></a><span class="lineno">   76</span><span class="comment"> * callbacks, factory, `enable_shared_from_this`) if it were directly in Node and Peer_socket.  On the</span></div>
<div class="line"><a id="l00077" name="l00077"></a><span class="lineno">   77</span><span class="comment"> * other hand the Strategy Pattern setup used here is nice for segregating the Drop Timer logic and</span></div>
<div class="line"><a id="l00078" name="l00078"></a><span class="lineno">   78</span><span class="comment"> * for future modification, and it does make Node (which is huge) much easier to understand.  So could</span></div>
<div class="line"><a id="l00079" name="l00079"></a><span class="lineno">   79</span><span class="comment"> * go either way... rewrite in Node and Peer_socket or leave it alone.</span></div>
<div class="line"><a id="l00080" name="l00080"></a><span class="lineno">   80</span><span class="comment"> *</span></div>
<div class="line"><a id="l00081" name="l00081"></a><span class="lineno">   81</span><span class="comment"> * We use a `Ptr`-emitting factory, because wrapping the object in a `Ptr` helps with some internal</span></div>
<div class="line"><a id="l00082" name="l00082"></a><span class="lineno">   82</span><span class="comment"> * book-keeping and is useful to the user as well.</span></div>
<div class="line"><a id="l00083" name="l00083"></a><span class="lineno">   83</span><span class="comment"> *</span></div>
<div class="line"><a id="l00084" name="l00084"></a><span class="lineno">   84</span><span class="comment"> * ### Regarding events ###</span></div>
<div class="line"><a id="l00085" name="l00085"></a><span class="lineno">   85</span><span class="comment"> * You&#39;ll note the interface is extremely simple: essentially, outside code just registers whenever</span></div>
<div class="line"><a id="l00086" name="l00086"></a><span class="lineno">   86</span><span class="comment"> * packet becomes In-flight (a/k/a is sent over wire); and the opposite.  This simplicity comes at</span></div>
<div class="line"><a id="l00087" name="l00087"></a><span class="lineno">   87</span><span class="comment"> * an implementation cost, because it requires us to keep -- *internally* -- an ordered (by send time) set</span></div>
<div class="line"><a id="l00088" name="l00088"></a><span class="lineno">   88</span><span class="comment"> * of packets currently In-flight.  Why do this?  Because the true events we are interested in are slightly</span></div>
<div class="line"><a id="l00089" name="l00089"></a><span class="lineno">   89</span><span class="comment"> * more complex than what the Drop_timer API exposes: we want to detect when no packets are In-flight and</span></div>
<div class="line"><a id="l00090" name="l00090"></a><span class="lineno">   90</span><span class="comment"> * suddenly a packet is sent off; the reverse; the acknowledgment of a packet that is NOT the oldest</span></div>
<div class="line"><a id="l00091" name="l00091"></a><span class="lineno">   91</span><span class="comment"> * one currently In-flight; and the changing of the oldest currently In-flight packet from packet A to</span></div>
<div class="line"><a id="l00092" name="l00092"></a><span class="lineno">   92</span><span class="comment"> * packet B =/= A.  (That&#39;s as of this writing; perhaps this set of events could change.)</span></div>
<div class="line"><a id="l00093" name="l00093"></a><span class="lineno">   93</span><span class="comment"> *</span></div>
<div class="line"><a id="l00094" name="l00094"></a><span class="lineno">   94</span><span class="comment"> * One might wonder whether it would be -- overall -- simpler to just have the event API of Drop_timer (the set of</span></div>
<div class="line"><a id="l00095" name="l00095"></a><span class="lineno">   95</span><span class="comment"> * on_...() methods) just be those exact events I just listed.  Then outside code could just call them when detecting</span></div>
<div class="line"><a id="l00096" name="l00096"></a><span class="lineno">   96</span><span class="comment"> * those events.  After all, Peer_socket has complex structures keeping track all sorts of details including how</span></div>
<div class="line"><a id="l00097" name="l00097"></a><span class="lineno">   97</span><span class="comment"> * many and which packets are In-flight, so Peer_socket and Node code could easily detect all those situations.</span></div>
<div class="line"><a id="l00098" name="l00098"></a><span class="lineno">   98</span><span class="comment"> *</span></div>
<div class="line"><a id="l00099" name="l00099"></a><span class="lineno">   99</span><span class="comment"> * In fact, that IS how Drop_timer was implemented in the past.  Here is why I changed it: There is a small</span></div>
<div class="line"><a id="l00100" name="l00100"></a><span class="lineno">  100</span><span class="comment"> * caveat about what &quot;In-flight&quot; means.  Peer_socket&#39;s `m_snd_flying_pkts_...` data structures define &quot;In-flight</span></div>
<div class="line"><a id="l00101" name="l00101"></a><span class="lineno">  101</span><span class="comment"> * packet&quot; as &quot;packet that has been determined to be fit to send over the wire, having passed the availability</span></div>
<div class="line"><a id="l00102" name="l00102"></a><span class="lineno">  102</span><span class="comment"> * and CWND constraints.&quot;  For Drop_timer&#39;s ideal operation, &quot;In-flight packet&quot; is defined as &quot;packet that has</span></div>
<div class="line"><a id="l00103" name="l00103"></a><span class="lineno">  103</span><span class="comment"> * been sent over the wire.&quot;  The practical difference between the two definitions is that the former may be</span></div>
<div class="line"><a id="l00104" name="l00104"></a><span class="lineno">  104</span><span class="comment"> * awaiting certain send pacing conditions to actually be sent off; whereas the latter means it has been sent</span></div>
<div class="line"><a id="l00105" name="l00105"></a><span class="lineno">  105</span><span class="comment"> * off -- period.  (See `struct Send_pacing_data` and related code for info on pacing.  Essentially, though,</span></div>
<div class="line"><a id="l00106" name="l00106"></a><span class="lineno">  106</span><span class="comment"> * any packet that&#39;s definitely going to be sent out barring existential disaster may be delayed a bit in a pacing</span></div>
<div class="line"><a id="l00107" name="l00107"></a><span class="lineno">  107</span><span class="comment"> * queue to avoid bunching up packets in the pipe.)  However, we lack a data structure that specifically</span></div>
<div class="line"><a id="l00108" name="l00108"></a><span class="lineno">  108</span><span class="comment"> * stores packets to have been sent off over the wire, except indirectly in Peer_socket::m_snd_flying_pkts_by_sent_when</span></div>
<div class="line"><a id="l00109" name="l00109"></a><span class="lineno">  109</span><span class="comment"> * minus Send_pacing_data::m_packet_q.  The former is unwieldy for our purposes, let along when combined with the</span></div>
<div class="line"><a id="l00110" name="l00110"></a><span class="lineno">  110</span><span class="comment"> * other.  So it made more sense to just let outside code report truly In-flight packets appearing and disappearing</span></div>
<div class="line"><a id="l00111" name="l00111"></a><span class="lineno">  111</span><span class="comment"> * to us, then we store the (rather minimal) information internally.  Thus we separate concerns and divide</span></div>
<div class="line"><a id="l00112" name="l00112"></a><span class="lineno">  112</span><span class="comment"> * labor among modules in an accurate fashion instead of Drop_timer becoming ultra-dependent on other modules&#39;</span></div>
<div class="line"><a id="l00113" name="l00113"></a><span class="lineno">  113</span><span class="comment"> * implementation details.  That said, there is probably some memory cost and (maybe) a little processor cycle</span></div>
<div class="line"><a id="l00114" name="l00114"></a><span class="lineno">  114</span><span class="comment"> * cost to this approach.  (One could also say that the pacing delay is so minor as to make it ignorable</span></div>
<div class="line"><a id="l00115" name="l00115"></a><span class="lineno">  115</span><span class="comment"> * here.  However, I decided I don&#39;t need the headache of wondering/worrying about that ad infinitum; and</span></div>
<div class="line"><a id="l00116" name="l00116"></a><span class="lineno">  116</span><span class="comment"> * solved the problem instead.)</span></div>
<div class="line"><a id="l00117" name="l00117"></a><span class="lineno">  117</span><span class="comment"> *</span></div>
<div class="line"><a id="l00118" name="l00118"></a><span class="lineno">  118</span><span class="comment"> * ### Update regarding events ###</span></div>
<div class="line"><a id="l00119" name="l00119"></a><span class="lineno">  119</span><span class="comment"> * In order to increase performance by smooshing together lots of little checks and</span></div>
<div class="line"><a id="l00120" name="l00120"></a><span class="lineno">  120</span><span class="comment"> * actions that might occur when handling lots of little events, namely received acknowledgments, the class</span></div>
<div class="line"><a id="l00121" name="l00121"></a><span class="lineno">  121</span><span class="comment"> * user must now bracket groups of `on_...()` method calls with start_contemporaneous_events() and</span></div>
<div class="line"><a id="l00122" name="l00122"></a><span class="lineno">  122</span><span class="comment"> * end_contemporaneous_events().  Thus each `on_...()` call performs only very basic/quick book-keeping; while</span></div>
<div class="line"><a id="l00123" name="l00123"></a><span class="lineno">  123</span><span class="comment"> * end_contemporaneous_events() is what compares the situation against what it was at start_contemporaneous_events()</span></div>
<div class="line"><a id="l00124" name="l00124"></a><span class="lineno">  124</span><span class="comment"> * and possibly detects the true events of interest that may actually trigger something (start timer, stop timer,</span></div>
<div class="line"><a id="l00125" name="l00125"></a><span class="lineno">  125</span><span class="comment"> * restart running timer).</span></div>
<div class="line"><a id="l00126" name="l00126"></a><span class="lineno">  126</span><span class="comment"> *</span></div>
<div class="line"><a id="l00127" name="l00127"></a><span class="lineno">  127</span><span class="comment"> * ### `Timer` vs util::schedule_task_from_now() ###</span></div>
<div class="line"><a id="l00128" name="l00128"></a><span class="lineno">  128</span><span class="comment"> * In other places we have tended to replace a `Timer` with the far simpler util::schedule_task_from_now() (etc.)</span></div>
<div class="line"><a id="l00129" name="l00129"></a><span class="lineno">  129</span><span class="comment"> * facility (which internally uses a `Timer` but hides its various annoyances and caveats).  Why not here?</span></div>
<div class="line"><a id="l00130" name="l00130"></a><span class="lineno">  130</span><span class="comment"> * Answer: We don&#39;t happen to use any of `Timer`&#39;s advanced features that the simpler facility lacks; we just</span></div>
<div class="line"><a id="l00131" name="l00131"></a><span class="lineno">  131</span><span class="comment"> * schedule and cancel, and the other facility supports those.  So that just leaves the potential performance</span></div>
<div class="line"><a id="l00132" name="l00132"></a><span class="lineno">  132</span><span class="comment"> * effects as the reason not to use the simpler facility (as listed in util::schedule_task_from_now() doc header).</span></div>
<div class="line"><a id="l00133" name="l00133"></a><span class="lineno">  133</span><span class="comment"> * The logic concerning the delay before each scheduled task, and how often it might be canceled and/or</span></div>
<div class="line"><a id="l00134" name="l00134"></a><span class="lineno">  134</span><span class="comment"> * rescheduled is not simple.  It&#39;s hard to make iron-clad guarantees, therefore, that using a single repeatedly-reused</span></div>
<div class="line"><a id="l00135" name="l00135"></a><span class="lineno">  135</span><span class="comment"> * `Timer` is no better perf-wise than using multiple schedulings using the simpler facility.  So we do the</span></div>
<div class="line"><a id="l00136" name="l00136"></a><span class="lineno">  136</span><span class="comment"> * perf-conservative thing and use `Timer` despite having to worry about a couple of the associated corner cases.</span></div>
<div class="line"><a id="l00137" name="l00137"></a><span class="lineno">  137</span><span class="comment"> *</span></div>
<div class="line"><a id="l00138" name="l00138"></a><span class="lineno">  138</span><span class="comment"> * Or to put it concisely: The timer logic here is complicated, so the perf and flexibility aspects of directly using</span></div>
<div class="line"><a id="l00139" name="l00139"></a><span class="lineno">  139</span><span class="comment"> * the advanced `Timer` feature are suitable.</span></div>
<div class="line"><a id="l00140" name="l00140"></a><span class="lineno">  140</span><span class="comment"> *</span></div>
<div class="line"><a id="l00141" name="l00141"></a><span class="lineno">  141</span><span class="comment"> * @todo Drop_timer has data members that are references to non-`const`.  These should be pointers for max consistency</span></div>
<div class="line"><a id="l00142" name="l00142"></a><span class="lineno">  142</span><span class="comment"> * of style with other code in the project (and that style is encouraged for certain good reasons).  Scour rest of</span></div>
<div class="line"><a id="l00143" name="l00143"></a><span class="lineno">  143</span><span class="comment"> * code for other such data members as well.</span></div>
<div class="line"><a id="l00144" name="l00144"></a><span class="lineno">  144</span><span class="comment"> */</span></div>
<div class="line"><a id="l00145" name="l00145"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html">  145</a></span><span class="keyword">class </span><a class="code hl_class" href="classflow_1_1net__flow_1_1Drop__timer.html">Drop_timer</a> :</div>
<div class="line"><a id="l00146" name="l00146"></a><span class="lineno">  146</span>  <span class="comment">// Endow us with shared_ptr&lt;&gt;s ::Ptr and ::Const_ptr (syntactic sugar).</span></div>
<div class="line"><a id="l00147" name="l00147"></a><span class="lineno">  147</span>  <span class="keyword">public</span> <a class="code hl_class" href="classflow_1_1util_1_1Shared__ptr__alias__holder.html">util::Shared_ptr_alias_holder</a>&lt;boost::shared_ptr&lt;Drop_timer&gt;&gt;,</div>
<div class="line"><a id="l00148" name="l00148"></a><span class="lineno">  148</span>  <span class="comment">// Allow access to Ptr(this) from inside Drop_timer methods.  Just call shared_from_this().</span></div>
<div class="line"><a id="l00149" name="l00149"></a><span class="lineno">  149</span>  <span class="keyword">public</span> boost::enable_shared_from_this&lt;Drop_timer&gt;,</div>
<div class="line"><a id="l00150" name="l00150"></a><span class="lineno">  150</span>  <span class="keyword">public</span> <a class="code hl_class" href="classflow_1_1log_1_1Log__context.html">log::Log_context</a>,</div>
<div class="line"><a id="l00151" name="l00151"></a><span class="lineno">  151</span>  <span class="keyword">private</span> boost::noncopyable</div>
<div class="line"><a id="l00152" name="l00152"></a><span class="lineno">  152</span>{</div>
<div class="line"><a id="l00153" name="l00153"></a><span class="lineno">  153</span><span class="keyword">public</span>:</div>
<div class="line"><a id="l00154" name="l00154"></a><span class="lineno">  154</span>  <span class="comment">// Types.</span></div>
<div class="line"><a id="l00155" name="l00155"></a><span class="lineno">  155</span><span class="comment"></span> </div>
<div class="line"><a id="l00156" name="l00156"></a><span class="lineno">  156</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00157" name="l00157"></a><span class="lineno">  157</span><span class="comment">   * Type to uniquely identify a packet sent over the wire in the socket to which this Drop_timer applies.</span></div>
<div class="line"><a id="l00158" name="l00158"></a><span class="lineno">  158</span><span class="comment">   * Caution: keep in sync with Peer_socket::order_num_t. That way Peer_socket</span></div>
<div class="line"><a id="l00159" name="l00159"></a><span class="lineno">  159</span><span class="comment">   * code can easily form a #packet_id_t from an `order_num_t` which, too, uniquely identifies a packet.</span></div>
<div class="line"><a id="l00160" name="l00160"></a><span class="lineno">  160</span><span class="comment">   * 0 is reserved, not to be used for any actual packets.</span></div>
<div class="line"><a id="l00161" name="l00161"></a><span class="lineno">  161</span><span class="comment">   */</span></div>
<div class="line"><a id="l00162" name="l00162"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">  162</a></span>  <span class="keyword">using </span><a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">packet_id_t</a> = <a class="code hl_typedef" href="classflow_1_1net__flow_1_1Sequence__number.html#ab307e12c0cf8cefbe7fb1ec8588af2a8">Sequence_number::seq_num_t</a>;</div>
<div class="line"><a id="l00163" name="l00163"></a><span class="lineno">  163</span> </div>
<div class="line"><a id="l00164" name="l00164"></a><span class="lineno">  164</span>  <span class="comment">// Constructors/destructor.</span></div>
<div class="line"><a id="l00165" name="l00165"></a><span class="lineno">  165</span><span class="comment"></span> </div>
<div class="line"><a id="l00166" name="l00166"></a><span class="lineno">  166</span><span class="comment">  /// Destructor.</span></div>
<div class="line"><a id="l00167" name="l00167"></a><span class="lineno">  167</span><span class="comment"></span>  <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a60e386c24490bd5880e9e8700e59ca6d">~Drop_timer</a>();</div>
<div class="line"><a id="l00168" name="l00168"></a><span class="lineno">  168</span> </div>
<div class="line"><a id="l00169" name="l00169"></a><span class="lineno">  169</span>  <span class="comment">// Methods.</span></div>
<div class="line"><a id="l00170" name="l00170"></a><span class="lineno">  170</span><span class="comment"></span> </div>
<div class="line"><a id="l00171" name="l00171"></a><span class="lineno">  171</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00172" name="l00172"></a><span class="lineno">  172</span><span class="comment">   * Constructs Drop_timer and returns a ref-counted pointer wrapping it.  Saves the &quot;action</span></div>
<div class="line"><a id="l00173" name="l00173"></a><span class="lineno">  173</span><span class="comment">   * callbacks&quot; to call when various events fire in this Drop_timer.  The callbacks may be placed</span></div>
<div class="line"><a id="l00174" name="l00174"></a><span class="lineno">  174</span><span class="comment">   * onto `*node_task_engine` in the manner of `post(Task_engine&amp;)`, at any future time until done()</span></div>
<div class="line"><a id="l00175" name="l00175"></a><span class="lineno">  175</span><span class="comment">   * is called.  At construction, the timer is guaranteed not to fire until the first `on_...()` call.</span></div>
<div class="line"><a id="l00176" name="l00176"></a><span class="lineno">  176</span><span class="comment">   *</span></div>
<div class="line"><a id="l00177" name="l00177"></a><span class="lineno">  177</span><span class="comment">   * After construction, call `on_...()` as events occur.  If an event described by the doc comment of</span></div>
<div class="line"><a id="l00178" name="l00178"></a><span class="lineno">  178</span><span class="comment">   * an `on_...()` method occurs, you MUST call it or results are undefined (the state machine breaks</span></div>
<div class="line"><a id="l00179" name="l00179"></a><span class="lineno">  179</span><span class="comment">   * down).</span></div>
<div class="line"><a id="l00180" name="l00180"></a><span class="lineno">  180</span><span class="comment">   *</span></div>
<div class="line"><a id="l00181" name="l00181"></a><span class="lineno">  181</span><span class="comment">   * @param logger_ptr</span></div>
<div class="line"><a id="l00182" name="l00182"></a><span class="lineno">  182</span><span class="comment">   *        The Logger implementation to use subsequently.</span></div>
<div class="line"><a id="l00183" name="l00183"></a><span class="lineno">  183</span><span class="comment">   * @param node_task_engine</span></div>
<div class="line"><a id="l00184" name="l00184"></a><span class="lineno">  184</span><span class="comment">   *        The containing Node&#39;s `&amp;m_task_engine`.  Asyncronous callbacks will be placed on it</span></div>
<div class="line"><a id="l00185" name="l00185"></a><span class="lineno">  185</span><span class="comment">   *        (see below).</span></div>
<div class="line"><a id="l00186" name="l00186"></a><span class="lineno">  186</span><span class="comment">   * @param sock_drop_timeout</span></div>
<div class="line"><a id="l00187" name="l00187"></a><span class="lineno">  187</span><span class="comment">   *        Pointer to the containing Peer_socket&#39;s `m_snd_drop_timeout.`  Drop_timer may write to this</span></div>
<div class="line"><a id="l00188" name="l00188"></a><span class="lineno">  188</span><span class="comment">   *        member if it feels the need to modify Drop Timeout value (as in RFC 6298 section 5.5)!</span></div>
<div class="line"><a id="l00189" name="l00189"></a><span class="lineno">  189</span><span class="comment">   * @param sock</span></div>
<div class="line"><a id="l00190" name="l00190"></a><span class="lineno">  190</span><span class="comment">   *        Pointer to the containing Peer_socket.  Access is read-only.</span></div>
<div class="line"><a id="l00191" name="l00191"></a><span class="lineno">  191</span><span class="comment">   * @param timer_failure</span></div>
<div class="line"><a id="l00192" name="l00192"></a><span class="lineno">  192</span><span class="comment">   *        Function `F` with signature `void F(const Error_code&amp; err_code)`.</span></div>
<div class="line"><a id="l00193" name="l00193"></a><span class="lineno">  193</span><span class="comment">   *        `F(&lt;failure code&gt;)` will be called if and only if there was an internal system timer</span></div>
<div class="line"><a id="l00194" name="l00194"></a><span class="lineno">  194</span><span class="comment">   *        failure.  Required action of `timer_failure()`: RST/close with the given error.</span></div>
<div class="line"><a id="l00195" name="l00195"></a><span class="lineno">  195</span><span class="comment">   * @param timer_fired</span></div>
<div class="line"><a id="l00196" name="l00196"></a><span class="lineno">  196</span><span class="comment">   *        Function `F` with signature `void F(bool drop_all_packets)`.  `F(drop_all_packets)` will be</span></div>
<div class="line"><a id="l00197" name="l00197"></a><span class="lineno">  197</span><span class="comment">   *        called if and only if the Drop Timer has fired.  Required action of `timer_fired()`: mark</span></div>
<div class="line"><a id="l00198" name="l00198"></a><span class="lineno">  198</span><span class="comment">   *        either all (if `drop_all_packets`) or just the earliest (otherwise) In-flight packet(s) as</span></div>
<div class="line"><a id="l00199" name="l00199"></a><span class="lineno">  199</span><span class="comment">   *        Dropped.</span></div>
<div class="line"><a id="l00200" name="l00200"></a><span class="lineno">  200</span><span class="comment">   * @return A ref-counted pointer wrapping a newly created Drop_timer as described above.</span></div>
<div class="line"><a id="l00201" name="l00201"></a><span class="lineno">  201</span><span class="comment">   */</span></div>
<div class="line"><a id="l00202" name="l00202"></a><span class="lineno">  202</span>  <span class="keyword">static</span> <a class="code hl_typedef" href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aa4f1af88393042e60159a3a67f0accbc">Ptr</a> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a64def367e38954d8a392cdf92fcc8f24">create_drop_timer</a>(<a class="code hl_class" href="classflow_1_1log_1_1Logger.html">log::Logger</a>* logger_ptr,</div>
<div class="line"><a id="l00203" name="l00203"></a><span class="lineno">  203</span>                               <a class="code hl_typedef" href="namespaceflow_1_1util.html#ac3e89a8a271b0ddc76ac2a0ce488dea4">util::Task_engine</a>* node_task_engine,</div>
<div class="line"><a id="l00204" name="l00204"></a><span class="lineno">  204</span>                               <a class="code hl_typedef" href="namespaceflow.html#a48799f1263cdeedec125be51a3db2b79">Fine_duration</a>* sock_drop_timeout,</div>
<div class="line"><a id="l00205" name="l00205"></a><span class="lineno">  205</span>                               <a class="code hl_typedef" href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aef7998db71c60eeb5d1e3d1a97c14886">Peer_socket::Const_ptr</a>&amp;&amp; sock,</div>
<div class="line"><a id="l00206" name="l00206"></a><span class="lineno">  206</span>                               <span class="keyword">const</span> <a class="code hl_class" href="classflow_1_1Function.html">Function</a>&lt;<span class="keywordtype">void</span> (<span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">Error_code</a>&amp; err_code)&gt;&amp; <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a40029643f0a6c7a2a6b20499ca4c5a67">timer_failure</a>,</div>
<div class="line"><a id="l00207" name="l00207"></a><span class="lineno">  207</span>                               <span class="keyword">const</span> <a class="code hl_class" href="classflow_1_1Function.html">Function</a>&lt;<span class="keywordtype">void</span> (<span class="keywordtype">bool</span> drop_all_packets)&gt;&amp; timer_fired);</div>
<div class="line"><a id="l00208" name="l00208"></a><span class="lineno">  208</span><span class="comment"></span> </div>
<div class="line"><a id="l00209" name="l00209"></a><span class="lineno">  209</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00210" name="l00210"></a><span class="lineno">  210</span><span class="comment">   * Indicates the start of a series of zero or more contemporary `on_*()` event calls, to be marked as finished</span></div>
<div class="line"><a id="l00211" name="l00211"></a><span class="lineno">  211</span><span class="comment">   * via end_contemporaneous_events(). Contemporary means to be treated as occurring in that order but essentially</span></div>
<div class="line"><a id="l00212" name="l00212"></a><span class="lineno">  212</span><span class="comment">   * simultaneously. (It is recommended but not enforced that they be registered in the same boost.asio task.)</span></div>
<div class="line"><a id="l00213" name="l00213"></a><span class="lineno">  213</span><span class="comment">   * This call should be followed by the 0+ `on_*()` calls; and finally end_contemporaneous_events(). Grouping events</span></div>
<div class="line"><a id="l00214" name="l00214"></a><span class="lineno">  214</span><span class="comment">   * in this way allows for better performance than, for example, a series of one-event groups.</span></div>
<div class="line"><a id="l00215" name="l00215"></a><span class="lineno">  215</span><span class="comment">   */</span></div>
<div class="line"><a id="l00216" name="l00216"></a><span class="lineno">  216</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#abf88c319884e5c5eb1b8f63c646e90ad">start_contemporaneous_events</a>();</div>
<div class="line"><a id="l00217" name="l00217"></a><span class="lineno">  217</span><span class="comment"></span> </div>
<div class="line"><a id="l00218" name="l00218"></a><span class="lineno">  218</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00219" name="l00219"></a><span class="lineno">  219</span><span class="comment">   * Indicates that a packet identified by the given unique ID has just been</span></div>
<div class="line"><a id="l00220" name="l00220"></a><span class="lineno">  220</span><span class="comment">   * sent over the wire (the low-level transport, currently UDP). Subtlety: Peer_socket may consider a packet</span></div>
<div class="line"><a id="l00221" name="l00221"></a><span class="lineno">  221</span><span class="comment">   * In-flight before it has actually been sent out over the wire, namely if it is queued in the pacing</span></div>
<div class="line"><a id="l00222" name="l00222"></a><span class="lineno">  222</span><span class="comment">   * module. This should be called only once it is actually sent. Note, however, that IF `on_packet_in_flight(P)`</span></div>
<div class="line"><a id="l00223" name="l00223"></a><span class="lineno">  223</span><span class="comment">   * is called, then indeed the packet identified by `P` _must_ be considered In-flight in the Peer_socket</span></div>
<div class="line"><a id="l00224" name="l00224"></a><span class="lineno">  224</span><span class="comment">   * sense. See Peer_socket::m_snd_flying_pkts_by_sent_when for definition of In-flight.</span></div>
<div class="line"><a id="l00225" name="l00225"></a><span class="lineno">  225</span><span class="comment">   *</span></div>
<div class="line"><a id="l00226" name="l00226"></a><span class="lineno">  226</span><span class="comment">   * A contemporary event group must be in progress via start_contemporaneous_events(); or behavior is undefined.</span></div>
<div class="line"><a id="l00227" name="l00227"></a><span class="lineno">  227</span><span class="comment">   *</span></div>
<div class="line"><a id="l00228" name="l00228"></a><span class="lineno">  228</span><span class="comment">   * @param packet_id</span></div>
<div class="line"><a id="l00229" name="l00229"></a><span class="lineno">  229</span><span class="comment">   *        ID of the packet that was sent out. This can be any number as long as it increases with each</span></div>
<div class="line"><a id="l00230" name="l00230"></a><span class="lineno">  230</span><span class="comment">   *        subsequent call to this method for `*this Drop_timer` (in particular, it&#39;ll therefore also be unique</span></div>
<div class="line"><a id="l00231" name="l00231"></a><span class="lineno">  231</span><span class="comment">   *        per Drop_timer). Behavior is undefined if this rule is not followed.</span></div>
<div class="line"><a id="l00232" name="l00232"></a><span class="lineno">  232</span><span class="comment">   */</span></div>
<div class="line"><a id="l00233" name="l00233"></a><span class="lineno">  233</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#afc1bf0978b04d454f5aa228a44550565">on_packet_in_flight</a>(<a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">packet_id_t</a> packet_id);</div>
<div class="line"><a id="l00234" name="l00234"></a><span class="lineno">  234</span><span class="comment"></span> </div>
<div class="line"><a id="l00235" name="l00235"></a><span class="lineno">  235</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00236" name="l00236"></a><span class="lineno">  236</span><span class="comment">   * Indicates that a packet for which on_packet_in_flight() was called is now no longer considered In-flight</span></div>
<div class="line"><a id="l00237" name="l00237"></a><span class="lineno">  237</span><span class="comment">   * in the Peer_socket sense; see Peer_socket::m_snd_flying_pkts_by_sent_when for definition of In-flight.</span></div>
<div class="line"><a id="l00238" name="l00238"></a><span class="lineno">  238</span><span class="comment">   * Since `on_packet_in_flight(P)` must be called only if `P` was then In-flight, `on_packet_no_longer_in_flight(P)`</span></div>
<div class="line"><a id="l00239" name="l00239"></a><span class="lineno">  239</span><span class="comment">   * can be called at most once and only after the former call.</span></div>
<div class="line"><a id="l00240" name="l00240"></a><span class="lineno">  240</span><span class="comment">   *</span></div>
<div class="line"><a id="l00241" name="l00241"></a><span class="lineno">  241</span><span class="comment">   * A contemporary event group must be in progress via start_contemporaneous_events(); or behavior is undefined.</span></div>
<div class="line"><a id="l00242" name="l00242"></a><span class="lineno">  242</span><span class="comment">   *</span></div>
<div class="line"><a id="l00243" name="l00243"></a><span class="lineno">  243</span><span class="comment">   * @param packet_id</span></div>
<div class="line"><a id="l00244" name="l00244"></a><span class="lineno">  244</span><span class="comment">   *        ID of a packet for which on_packet_in_flight() has been called exactly once for `*this`.</span></div>
<div class="line"><a id="l00245" name="l00245"></a><span class="lineno">  245</span><span class="comment">   *        Otherwise behavior is undefined.</span></div>
<div class="line"><a id="l00246" name="l00246"></a><span class="lineno">  246</span><span class="comment">   */</span></div>
<div class="line"><a id="l00247" name="l00247"></a><span class="lineno">  247</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a5d1fff72b5c044cba0651de0508553e0">on_packet_no_longer_in_flight</a>(<a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">packet_id_t</a> packet_id);</div>
<div class="line"><a id="l00248" name="l00248"></a><span class="lineno">  248</span><span class="comment"></span> </div>
<div class="line"><a id="l00249" name="l00249"></a><span class="lineno">  249</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00250" name="l00250"></a><span class="lineno">  250</span><span class="comment">   * Equivalent to `on_packet_no_longer_in_flight(P)`, for all `P` currently In-flight as registered by</span></div>
<div class="line"><a id="l00251" name="l00251"></a><span class="lineno">  251</span><span class="comment">   * `on_packet_in_flight(P)`.  When you know it would be correct, call it instead of the former method many times</span></div>
<div class="line"><a id="l00252" name="l00252"></a><span class="lineno">  252</span><span class="comment">   * for better efficiency.  (Do not do &quot;both.&quot;  Trying to register more than once that `P` is no longer In-flight leads</span></div>
<div class="line"><a id="l00253" name="l00253"></a><span class="lineno">  253</span><span class="comment">   * to undefined behavior.)</span></div>
<div class="line"><a id="l00254" name="l00254"></a><span class="lineno">  254</span><span class="comment">   *</span></div>
<div class="line"><a id="l00255" name="l00255"></a><span class="lineno">  255</span><span class="comment">   * Calling this when no packets are In-flight already leads to undefined behavior.</span></div>
<div class="line"><a id="l00256" name="l00256"></a><span class="lineno">  256</span><span class="comment">   *</span></div>
<div class="line"><a id="l00257" name="l00257"></a><span class="lineno">  257</span><span class="comment">   * A contemporary event group must be in progress via start_contemporaneous_events(); or behavior is undefined.</span></div>
<div class="line"><a id="l00258" name="l00258"></a><span class="lineno">  258</span><span class="comment">   */</span></div>
<div class="line"><a id="l00259" name="l00259"></a><span class="lineno">  259</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#ac5a7ab3108a915999e95ccf705006ccd">on_no_packets_in_flight_any_longer</a>();</div>
<div class="line"><a id="l00260" name="l00260"></a><span class="lineno">  260</span><span class="comment"></span> </div>
<div class="line"><a id="l00261" name="l00261"></a><span class="lineno">  261</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00262" name="l00262"></a><span class="lineno">  262</span><span class="comment">   * Indicates that a packet for which on_packet_in_flight() was called has just been validly acked.</span></div>
<div class="line"><a id="l00263" name="l00263"></a><span class="lineno">  263</span><span class="comment">   * To be validly acked means that an acknowledgment was received while the packet was considered In-flight in</span></div>
<div class="line"><a id="l00264" name="l00264"></a><span class="lineno">  264</span><span class="comment">   * the Peer_socket sense. See Peer_socket::m_snd_flying_pkts_by_sent_when for definition of In-flight.</span></div>
<div class="line"><a id="l00265" name="l00265"></a><span class="lineno">  265</span><span class="comment">   *</span></div>
<div class="line"><a id="l00266" name="l00266"></a><span class="lineno">  266</span><span class="comment">   * Such a packet also requires an on_packet_no_longer_in_flight() call. You must call on_ack() first; and the latter</span></div>
<div class="line"><a id="l00267" name="l00267"></a><span class="lineno">  267</span><span class="comment">   * subsequently. Otherwise behavior is undefined.</span></div>
<div class="line"><a id="l00268" name="l00268"></a><span class="lineno">  268</span><span class="comment">   *</span></div>
<div class="line"><a id="l00269" name="l00269"></a><span class="lineno">  269</span><span class="comment">   * A contemporary event group must be in progress via start_contemporaneous_events(); or behavior is undefined.</span></div>
<div class="line"><a id="l00270" name="l00270"></a><span class="lineno">  270</span><span class="comment">   *</span></div>
<div class="line"><a id="l00271" name="l00271"></a><span class="lineno">  271</span><span class="comment">   * @param packet_id</span></div>
<div class="line"><a id="l00272" name="l00272"></a><span class="lineno">  272</span><span class="comment">   *        ID of a packet for which on_packet_in_flight() has been called exactly once for *this.</span></div>
<div class="line"><a id="l00273" name="l00273"></a><span class="lineno">  273</span><span class="comment">   *        Otherwise behavior is undefined.</span></div>
<div class="line"><a id="l00274" name="l00274"></a><span class="lineno">  274</span><span class="comment">   */</span></div>
<div class="line"><a id="l00275" name="l00275"></a><span class="lineno">  275</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a477fd69a6978cc228b8e80611aa234ba">on_ack</a>(<a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">packet_id_t</a> packet_id);</div>
<div class="line"><a id="l00276" name="l00276"></a><span class="lineno">  276</span><span class="comment"></span> </div>
<div class="line"><a id="l00277" name="l00277"></a><span class="lineno">  277</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00278" name="l00278"></a><span class="lineno">  278</span><span class="comment">   * Finishes the group started by start start_contemporaneous_events(). This may trigger various on-event behavior</span></div>
<div class="line"><a id="l00279" name="l00279"></a><span class="lineno">  279</span><span class="comment">   * such as starting, stopping, or restarting the Drop_timer.</span></div>
<div class="line"><a id="l00280" name="l00280"></a><span class="lineno">  280</span><span class="comment">   */</span></div>
<div class="line"><a id="l00281" name="l00281"></a><span class="lineno">  281</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a45d4cf2dfecc2cd5c35f452cd7c8d05d">end_contemporaneous_events</a>();</div>
<div class="line"><a id="l00282" name="l00282"></a><span class="lineno">  282</span><span class="comment"></span> </div>
<div class="line"><a id="l00283" name="l00283"></a><span class="lineno">  283</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00284" name="l00284"></a><span class="lineno">  284</span><span class="comment">   * Causes the Drop_timer to guarantee none of the action callbacks provided at construction will</span></div>
<div class="line"><a id="l00285" name="l00285"></a><span class="lineno">  285</span><span class="comment">   * be called from this point on.  Call this once you have no need of the Drop_timer (probably upon</span></div>
<div class="line"><a id="l00286" name="l00286"></a><span class="lineno">  286</span><span class="comment">   * exiting Peer_socket::Int_state::S_ESTABLISHED).  Subsequent calls to done() are harmless.</span></div>
<div class="line"><a id="l00287" name="l00287"></a><span class="lineno">  287</span><span class="comment">   *</span></div>
<div class="line"><a id="l00288" name="l00288"></a><span class="lineno">  288</span><span class="comment">   * Behavior is undefined if calling any other methods after done().</span></div>
<div class="line"><a id="l00289" name="l00289"></a><span class="lineno">  289</span><span class="comment">   */</span></div>
<div class="line"><a id="l00290" name="l00290"></a><span class="lineno">  290</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#ab6b96e0200579afdee1bf1ce58ab5ad2">done</a>();</div>
<div class="line"><a id="l00291" name="l00291"></a><span class="lineno">  291</span> </div>
<div class="line"><a id="l00292" name="l00292"></a><span class="lineno">  292</span><span class="keyword">private</span>:</div>
<div class="line"><a id="l00293" name="l00293"></a><span class="lineno">  293</span> </div>
<div class="line"><a id="l00294" name="l00294"></a><span class="lineno">  294</span>  <span class="comment">// Types.</span></div>
<div class="line"><a id="l00295" name="l00295"></a><span class="lineno">  295</span><span class="comment"></span> </div>
<div class="line"><a id="l00296" name="l00296"></a><span class="lineno">  296</span><span class="comment">  /// The counter type used to distinguish a given start_timer() call from any other such call (for this object).</span></div>
<div class="line"><a id="l00297" name="l00297"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db6f435dfc65b7bd4b539467f1c3ec">  297</a></span><span class="comment"></span>  <span class="keyword">using </span><a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db6f435dfc65b7bd4b539467f1c3ec">timer_wait_id_t</a> = uint64_t;</div>
<div class="line"><a id="l00298" name="l00298"></a><span class="lineno">  298</span> </div>
<div class="line"><a id="l00299" name="l00299"></a><span class="lineno">  299</span>  <span class="comment">// Constructors.</span></div>
<div class="line"><a id="l00300" name="l00300"></a><span class="lineno">  300</span><span class="comment"></span> </div>
<div class="line"><a id="l00301" name="l00301"></a><span class="lineno">  301</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00302" name="l00302"></a><span class="lineno">  302</span><span class="comment">   * Constructs Drop_timer as described in the factory constructor create_drop_timer().</span></div>
<div class="line"><a id="l00303" name="l00303"></a><span class="lineno">  303</span><span class="comment">   * Why have the factory method?  We guarantee that this won&#39;t get deleted before the timer</span></div>
<div class="line"><a id="l00304" name="l00304"></a><span class="lineno">  304</span><span class="comment">   * callback executes (causing a crash therein), by passing a `Ptr(this)` to</span></div>
<div class="line"><a id="l00305" name="l00305"></a><span class="lineno">  305</span><span class="comment">   * `basic_waitable_timer::async_wait()`.  However that can only work if all users of the object also</span></div>
<div class="line"><a id="l00306" name="l00306"></a><span class="lineno">  306</span><span class="comment">   * access it by a sharing `Ptr`.  Thus we only provide access to the outside via a `Ptr` (the</span></div>
<div class="line"><a id="l00307" name="l00307"></a><span class="lineno">  307</span><span class="comment">   * factory).</span></div>
<div class="line"><a id="l00308" name="l00308"></a><span class="lineno">  308</span><span class="comment">   *</span></div>
<div class="line"><a id="l00309" name="l00309"></a><span class="lineno">  309</span><span class="comment">   * @param logger</span></div>
<div class="line"><a id="l00310" name="l00310"></a><span class="lineno">  310</span><span class="comment">   *        See create_drop_timer().</span></div>
<div class="line"><a id="l00311" name="l00311"></a><span class="lineno">  311</span><span class="comment">   * @param node_task_engine</span></div>
<div class="line"><a id="l00312" name="l00312"></a><span class="lineno">  312</span><span class="comment">   *        See create_drop_timer().</span></div>
<div class="line"><a id="l00313" name="l00313"></a><span class="lineno">  313</span><span class="comment">   * @param sock_drop_timeout</span></div>
<div class="line"><a id="l00314" name="l00314"></a><span class="lineno">  314</span><span class="comment">   *        See create_drop_timer().</span></div>
<div class="line"><a id="l00315" name="l00315"></a><span class="lineno">  315</span><span class="comment">   * @param sock</span></div>
<div class="line"><a id="l00316" name="l00316"></a><span class="lineno">  316</span><span class="comment">   *        See create_drop_timer().</span></div>
<div class="line"><a id="l00317" name="l00317"></a><span class="lineno">  317</span><span class="comment">   * @param timer_failure</span></div>
<div class="line"><a id="l00318" name="l00318"></a><span class="lineno">  318</span><span class="comment">   *        See create_drop_timer().</span></div>
<div class="line"><a id="l00319" name="l00319"></a><span class="lineno">  319</span><span class="comment">   * @param timer_fired</span></div>
<div class="line"><a id="l00320" name="l00320"></a><span class="lineno">  320</span><span class="comment">   *        See create_drop_timer().</span></div>
<div class="line"><a id="l00321" name="l00321"></a><span class="lineno">  321</span><span class="comment">   */</span></div>
<div class="line"><a id="l00322" name="l00322"></a><span class="lineno">  322</span>  <span class="keyword">explicit</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a9c94b0191a80afb98b6da4a2d0b47a46">Drop_timer</a>(<a class="code hl_class" href="classflow_1_1log_1_1Logger.html">log::Logger</a>* logger,</div>
<div class="line"><a id="l00323" name="l00323"></a><span class="lineno">  323</span>                      <a class="code hl_typedef" href="namespaceflow_1_1util.html#ac3e89a8a271b0ddc76ac2a0ce488dea4">util::Task_engine</a>* node_task_engine,</div>
<div class="line"><a id="l00324" name="l00324"></a><span class="lineno">  324</span>                      <a class="code hl_typedef" href="namespaceflow.html#a48799f1263cdeedec125be51a3db2b79">Fine_duration</a>* sock_drop_timeout,</div>
<div class="line"><a id="l00325" name="l00325"></a><span class="lineno">  325</span>                      <a class="code hl_typedef" href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aef7998db71c60eeb5d1e3d1a97c14886">Peer_socket::Const_ptr</a>&amp;&amp; sock,</div>
<div class="line"><a id="l00326" name="l00326"></a><span class="lineno">  326</span>                      <span class="keyword">const</span> <a class="code hl_class" href="classflow_1_1Function.html">Function</a>&lt;<span class="keywordtype">void</span> (<span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">Error_code</a>&amp; err_code)&gt;&amp; <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a40029643f0a6c7a2a6b20499ca4c5a67">timer_failure</a>,</div>
<div class="line"><a id="l00327" name="l00327"></a><span class="lineno">  327</span>                      <span class="keyword">const</span> <a class="code hl_class" href="classflow_1_1Function.html">Function</a>&lt;<span class="keywordtype">void</span> (<span class="keywordtype">bool</span> drop_all_packets)&gt;&amp; timer_fired);</div>
<div class="line"><a id="l00328" name="l00328"></a><span class="lineno">  328</span> </div>
<div class="line"><a id="l00329" name="l00329"></a><span class="lineno">  329</span>  <span class="comment">// Methods.</span></div>
<div class="line"><a id="l00330" name="l00330"></a><span class="lineno">  330</span><span class="comment"></span> </div>
<div class="line"><a id="l00331" name="l00331"></a><span class="lineno">  331</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00332" name="l00332"></a><span class="lineno">  332</span><span class="comment">   * Starts a new wait on the timer, so that is it asynchronously triggered according to the current</span></div>
<div class="line"><a id="l00333" name="l00333"></a><span class="lineno">  333</span><span class="comment">   * DTO value.  Pre-condition: `!m_timer_running`.</span></div>
<div class="line"><a id="l00334" name="l00334"></a><span class="lineno">  334</span><span class="comment">   */</span></div>
<div class="line"><a id="l00335" name="l00335"></a><span class="lineno">  335</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a4a5f0bbb91232e17e258722e4dfa237b">start_timer</a>();</div>
<div class="line"><a id="l00336" name="l00336"></a><span class="lineno">  336</span><span class="comment"></span> </div>
<div class="line"><a id="l00337" name="l00337"></a><span class="lineno">  337</span><span class="comment">  /// Invalidates the running asynchronous wait on #m_timer.  Pre-condition: #m_timer_running.</span></div>
<div class="line"><a id="l00338" name="l00338"></a><span class="lineno">  338</span><span class="comment"></span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#ad655d5461aa5a6bf9a80d28e4a4fdd77">disable_timer</a>();</div>
<div class="line"><a id="l00339" name="l00339"></a><span class="lineno">  339</span><span class="comment"></span> </div>
<div class="line"><a id="l00340" name="l00340"></a><span class="lineno">  340</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00341" name="l00341"></a><span class="lineno">  341</span><span class="comment">   * Called by boost.asio when the Drop Timer fires; disables timer and calls an outside action</span></div>
<div class="line"><a id="l00342" name="l00342"></a><span class="lineno">  342</span><span class="comment">   * callback (given in constructor).  If #m_done or `m_current_wait_id != wait_id` or `err_code` is</span></div>
<div class="line"><a id="l00343" name="l00343"></a><span class="lineno">  343</span><span class="comment">   * `operation_aborted` (meaning this invokation by boost.asio is obsolete and replaced by a</span></div>
<div class="line"><a id="l00344" name="l00344"></a><span class="lineno">  344</span><span class="comment">   * subsequent async_wait(), or canceled), does nothing.</span></div>
<div class="line"><a id="l00345" name="l00345"></a><span class="lineno">  345</span><span class="comment">   *</span></div>
<div class="line"><a id="l00346" name="l00346"></a><span class="lineno">  346</span><span class="comment">   * @param wait_id</span></div>
<div class="line"><a id="l00347" name="l00347"></a><span class="lineno">  347</span><span class="comment">   *        The value of #m_current_wait_id at the time that `m_timer.async_wait()` was called with</span></div>
<div class="line"><a id="l00348" name="l00348"></a><span class="lineno">  348</span><span class="comment">   *        this method invokation as an argument.</span></div>
<div class="line"><a id="l00349" name="l00349"></a><span class="lineno">  349</span><span class="comment">   * @param prevent_destruction</span></div>
<div class="line"><a id="l00350" name="l00350"></a><span class="lineno">  350</span><span class="comment">   *        `shared_from_this()` at the time of `m_timer.async_wait()`.  It assures `this` cannot be</span></div>
<div class="line"><a id="l00351" name="l00351"></a><span class="lineno">  351</span><span class="comment">   *        deleted until this handle_timer_firing() is called and returns.</span></div>
<div class="line"><a id="l00352" name="l00352"></a><span class="lineno">  352</span><span class="comment">   * @param sys_err_code</span></div>
<div class="line"><a id="l00353" name="l00353"></a><span class="lineno">  353</span><span class="comment">   *        boost.asio error code indicating the circumstances of the callback executing.  If this</span></div>
<div class="line"><a id="l00354" name="l00354"></a><span class="lineno">  354</span><span class="comment">   *        is `boost::error::operation_aborted`, method does nothing.</span></div>
<div class="line"><a id="l00355" name="l00355"></a><span class="lineno">  355</span><span class="comment">   */</span></div>
<div class="line"><a id="l00356" name="l00356"></a><span class="lineno">  356</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#aaf4f0fce1d41e16309beca40a126e2f0">handle_timer_firing</a>(<a class="code hl_typedef" href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aa4f1af88393042e60159a3a67f0accbc">Ptr</a> prevent_destruction,</div>
<div class="line"><a id="l00357" name="l00357"></a><span class="lineno">  357</span>                           <a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db6f435dfc65b7bd4b539467f1c3ec">timer_wait_id_t</a> wait_id,</div>
<div class="line"><a id="l00358" name="l00358"></a><span class="lineno">  358</span>                           <span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">Error_code</a>&amp; sys_err_code);</div>
<div class="line"><a id="l00359" name="l00359"></a><span class="lineno">  359</span><span class="comment"></span> </div>
<div class="line"><a id="l00360" name="l00360"></a><span class="lineno">  360</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00361" name="l00361"></a><span class="lineno">  361</span><span class="comment">   * Called by boost.asio after we post it, in the event of some timer error.  If #m_done, does</span></div>
<div class="line"><a id="l00362" name="l00362"></a><span class="lineno">  362</span><span class="comment">   * nothing (meaning the object was turned off before this had a chance to be executed).  Otherwise</span></div>
<div class="line"><a id="l00363" name="l00363"></a><span class="lineno">  363</span><span class="comment">   * executes the `m_timer_failure()` callback.</span></div>
<div class="line"><a id="l00364" name="l00364"></a><span class="lineno">  364</span><span class="comment">   *</span></div>
<div class="line"><a id="l00365" name="l00365"></a><span class="lineno">  365</span><span class="comment">   * @param prevent_destruction</span></div>
<div class="line"><a id="l00366" name="l00366"></a><span class="lineno">  366</span><span class="comment">   *        `shared_from_this()` at the time of `m_timer.async_wait()`.  It assures `this` cannot be</span></div>
<div class="line"><a id="l00367" name="l00367"></a><span class="lineno">  367</span><span class="comment">   *        deleted until `this-&gt;handle_timer_firing()` is called and returns.</span></div>
<div class="line"><a id="l00368" name="l00368"></a><span class="lineno">  368</span><span class="comment">   * @param err_code</span></div>
<div class="line"><a id="l00369" name="l00369"></a><span class="lineno">  369</span><span class="comment">   *        The portable error to pass to the `m_timer_failure()`.</span></div>
<div class="line"><a id="l00370" name="l00370"></a><span class="lineno">  370</span><span class="comment">   */</span></div>
<div class="line"><a id="l00371" name="l00371"></a><span class="lineno">  371</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1net__flow_1_1Drop__timer.html#a40029643f0a6c7a2a6b20499ca4c5a67">timer_failure</a>(<a class="code hl_typedef" href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aa4f1af88393042e60159a3a67f0accbc">Ptr</a> prevent_destruction, <span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">Error_code</a>&amp; err_code);</div>
<div class="line"><a id="l00372" name="l00372"></a><span class="lineno">  372</span> </div>
<div class="line"><a id="l00373" name="l00373"></a><span class="lineno">  373</span>  <span class="comment">// Data.</span></div>
<div class="line"><a id="l00374" name="l00374"></a><span class="lineno">  374</span><span class="comment"></span> </div>
<div class="line"><a id="l00375" name="l00375"></a><span class="lineno">  375</span><span class="comment">  /// Node::m_task_engine of the containing Node.  Used to schedule timer events.</span></div>
<div class="line"><a id="l00376" name="l00376"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#ac3cfab1594111b3c3254eebc84591908">  376</a></span><span class="comment"></span>  <a class="code hl_typedef" href="namespaceflow_1_1util.html#ac3e89a8a271b0ddc76ac2a0ce488dea4">util::Task_engine</a>&amp; <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#ac3cfab1594111b3c3254eebc84591908">m_node_task_engine</a>;</div>
<div class="line"><a id="l00377" name="l00377"></a><span class="lineno">  377</span><span class="comment"></span> </div>
<div class="line"><a id="l00378" name="l00378"></a><span class="lineno">  378</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00379" name="l00379"></a><span class="lineno">  379</span><span class="comment">   * Reference to the containing Peer_socket&#39;s Peer_socket::m_snd_drop_timeout data member (= DTO, Drop Timeout,</span></div>
<div class="line"><a id="l00380" name="l00380"></a><span class="lineno">  380</span><span class="comment">   * RTO).  Why is this not `const`?  Because under certain policies this object is allowed to</span></div>
<div class="line"><a id="l00381" name="l00381"></a><span class="lineno">  381</span><span class="comment">   * CHANGE the value of the DTO.  E.g., RFC 6298 says that RTO MUST be doubled each time the</span></div>
<div class="line"><a id="l00382" name="l00382"></a><span class="lineno">  382</span><span class="comment">   * Retransmit Timer fires.  (However a subsequent RTT measurement and SRTT recalculation will</span></div>
<div class="line"><a id="l00383" name="l00383"></a><span class="lineno">  383</span><span class="comment">   * change it back to the normally computed value.)</span></div>
<div class="line"><a id="l00384" name="l00384"></a><span class="lineno">  384</span><span class="comment">   */</span></div>
<div class="line"><a id="l00385" name="l00385"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db83f50aec60604de55d01e15ea403">  385</a></span>  <a class="code hl_typedef" href="namespaceflow.html#a48799f1263cdeedec125be51a3db2b79">Fine_duration</a>&amp; <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db83f50aec60604de55d01e15ea403">m_sock_drop_timeout</a>;</div>
<div class="line"><a id="l00386" name="l00386"></a><span class="lineno">  386</span><span class="comment"></span> </div>
<div class="line"><a id="l00387" name="l00387"></a><span class="lineno">  387</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00388" name="l00388"></a><span class="lineno">  388</span><span class="comment">   * The containing Peer_socket (note that this is read-only access).  This may be used</span></div>
<div class="line"><a id="l00389" name="l00389"></a><span class="lineno">  389</span><span class="comment">   * to, at least, get the time point at which a packet was originally sent, to schedule the timer,</span></div>
<div class="line"><a id="l00390" name="l00390"></a><span class="lineno">  390</span><span class="comment">   * as well to get socket options related to Drop Timer.</span></div>
<div class="line"><a id="l00391" name="l00391"></a><span class="lineno">  391</span><span class="comment">   */</span></div>
<div class="line"><a id="l00392" name="l00392"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a7ab957ddc07d6289d1b42d6686173533">  392</a></span>  <span class="keyword">const</span> <a class="code hl_typedef" href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aef7998db71c60eeb5d1e3d1a97c14886">Peer_socket::Const_ptr</a> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a7ab957ddc07d6289d1b42d6686173533">m_sock</a>;</div>
<div class="line"><a id="l00393" name="l00393"></a><span class="lineno">  393</span><span class="comment"></span> </div>
<div class="line"><a id="l00394" name="l00394"></a><span class="lineno">  394</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00395" name="l00395"></a><span class="lineno">  395</span><span class="comment">   * The Drop Timer itself.  This class maintains it (including based on input events reported by</span></div>
<div class="line"><a id="l00396" name="l00396"></a><span class="lineno">  396</span><span class="comment">   * the user) and informs the user when it expires and what to do about it if so.</span></div>
<div class="line"><a id="l00397" name="l00397"></a><span class="lineno">  397</span><span class="comment">   */</span></div>
<div class="line"><a id="l00398" name="l00398"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#ad5dfc3cd2f8e5e4d28c49e28ee5c221f">  398</a></span>  <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae7416d64d2989051104bb396e28e15e6">util::Timer</a> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#ad5dfc3cd2f8e5e4d28c49e28ee5c221f">m_timer</a>;</div>
<div class="line"><a id="l00399" name="l00399"></a><span class="lineno">  399</span><span class="comment"></span> </div>
<div class="line"><a id="l00400" name="l00400"></a><span class="lineno">  400</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00401" name="l00401"></a><span class="lineno">  401</span><span class="comment">   * Is there an active (non-obsolete, not-canceled) asynchronous wait in progress on #m_timer?  More</span></div>
<div class="line"><a id="l00402" name="l00402"></a><span class="lineno">  402</span><span class="comment">   * precisely, this is `true` if the latest start_timer() call was later than the latest</span></div>
<div class="line"><a id="l00403" name="l00403"></a><span class="lineno">  403</span><span class="comment">   * disable_timer() or handle_timer_firing(), or if start_timer() has been called but</span></div>
<div class="line"><a id="l00404" name="l00404"></a><span class="lineno">  404</span><span class="comment">   * disable_timer() or handle_timer_firing() has not.</span></div>
<div class="line"><a id="l00405" name="l00405"></a><span class="lineno">  405</span><span class="comment">   *</span></div>
<div class="line"><a id="l00406" name="l00406"></a><span class="lineno">  406</span><span class="comment">   * #m_timer_running should not be checked unless `!m_done`.</span></div>
<div class="line"><a id="l00407" name="l00407"></a><span class="lineno">  407</span><span class="comment">   */</span></div>
<div class="line"><a id="l00408" name="l00408"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a9528326a35b021bb859bed948ae3d7a4">  408</a></span>  <span class="keywordtype">bool</span> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a9528326a35b021bb859bed948ae3d7a4">m_timer_running</a>;</div>
<div class="line"><a id="l00409" name="l00409"></a><span class="lineno">  409</span><span class="comment"></span> </div>
<div class="line"><a id="l00410" name="l00410"></a><span class="lineno">  410</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00411" name="l00411"></a><span class="lineno">  411</span><span class="comment">   * Unique (within this object) identifier of the last start_timer() call.  Each time start_timer()</span></div>
<div class="line"><a id="l00412" name="l00412"></a><span class="lineno">  412</span><span class="comment">   * calls `boost::asio::basic_waitable_timer::async_wait()`, it passes `++m_current_wait_id` to the timer</span></div>
<div class="line"><a id="l00413" name="l00413"></a><span class="lineno">  413</span><span class="comment">   * firing callback.  Then when that callback runs, it can check whether this passed `wait_id` is</span></div>
<div class="line"><a id="l00414" name="l00414"></a><span class="lineno">  414</span><span class="comment">   * equal to #m_current_wait_id; if not then it knows the callback is called for an obsolete wait</span></div>
<div class="line"><a id="l00415" name="l00415"></a><span class="lineno">  415</span><span class="comment">   * and should do nothing.  This is to help deal with the fact that a `basic_waitable_timer` callback can</span></div>
<div class="line"><a id="l00416" name="l00416"></a><span class="lineno">  416</span><span class="comment">   * fire after it is `cancel()`ed if the callback was already queued by the time `cancel()` is called</span></div>
<div class="line"><a id="l00417" name="l00417"></a><span class="lineno">  417</span><span class="comment">   * (see `boost::asio::basic_waitable_timer` documentation).</span></div>
<div class="line"><a id="l00418" name="l00418"></a><span class="lineno">  418</span><span class="comment">   *</span></div>
<div class="line"><a id="l00419" name="l00419"></a><span class="lineno">  419</span><span class="comment">   * For example, if I schedule wait 1, and it is queued to fire 5 seconds later, but at that point</span></div>
<div class="line"><a id="l00420" name="l00420"></a><span class="lineno">  420</span><span class="comment">   * something causes me to cancel and schedule wait 2 for another 5 seconds later, then wait 1&#39;s</span></div>
<div class="line"><a id="l00421" name="l00421"></a><span class="lineno">  421</span><span class="comment">   * callback, though soon called, will detect that `wait_id &lt; m_current_wait_id` and do nothing, as</span></div>
<div class="line"><a id="l00422" name="l00422"></a><span class="lineno">  422</span><span class="comment">   * desired.  Another 5 seconds later, wait 2&#39;s callback will see that `wait_id == m_current_wait_id`</span></div>
<div class="line"><a id="l00423" name="l00423"></a><span class="lineno">  423</span><span class="comment">   * and do stuff, as desired.</span></div>
<div class="line"><a id="l00424" name="l00424"></a><span class="lineno">  424</span><span class="comment">   *</span></div>
<div class="line"><a id="l00425" name="l00425"></a><span class="lineno">  425</span><span class="comment">   * This must only change via increment and start at zero.  Wrap-around is impossible due to the</span></div>
<div class="line"><a id="l00426" name="l00426"></a><span class="lineno">  426</span><span class="comment">   * range of #timer_wait_id_t and the time periods practically involved.</span></div>
<div class="line"><a id="l00427" name="l00427"></a><span class="lineno">  427</span><span class="comment">   *</span></div>
<div class="line"><a id="l00428" name="l00428"></a><span class="lineno">  428</span><span class="comment">   * #m_current_wait_id should not be checked unless #m_timer_running.</span></div>
<div class="line"><a id="l00429" name="l00429"></a><span class="lineno">  429</span><span class="comment">   */</span></div>
<div class="line"><a id="l00430" name="l00430"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#aa9af1ac250a1a40f3c8df5878e55b98c">  430</a></span>  <a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db6f435dfc65b7bd4b539467f1c3ec">timer_wait_id_t</a> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#aa9af1ac250a1a40f3c8df5878e55b98c">m_current_wait_id</a>;</div>
<div class="line"><a id="l00431" name="l00431"></a><span class="lineno">  431</span><span class="comment"></span> </div>
<div class="line"><a id="l00432" name="l00432"></a><span class="lineno">  432</span><span class="comment">  /// `true` if and only if done() has been called.  Starts at `false`, can only change to `true`.</span></div>
<div class="line"><a id="l00433" name="l00433"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a9de653d7372110ffd176ef34e916a7dd">  433</a></span><span class="comment"></span>  <span class="keywordtype">bool</span> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a9de653d7372110ffd176ef34e916a7dd">m_done</a>;</div>
<div class="line"><a id="l00434" name="l00434"></a><span class="lineno">  434</span><span class="comment"></span> </div>
<div class="line"><a id="l00435" name="l00435"></a><span class="lineno">  435</span><span class="comment">  /// Called on error.  See Drop_timer constructor.</span></div>
<div class="line"><a id="l00436" name="l00436"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a21e78b9da6196043e1c05589c46911fa">  436</a></span><span class="comment"></span>  <a class="code hl_class" href="classflow_1_1Function.html">Function</a>&lt;void (<span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">Error_code</a>&amp; err_code)&gt; <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a21e78b9da6196043e1c05589c46911fa">m_timer_failure</a>;</div>
<div class="line"><a id="l00437" name="l00437"></a><span class="lineno">  437</span><span class="comment"></span> </div>
<div class="line"><a id="l00438" name="l00438"></a><span class="lineno">  438</span><span class="comment">  /// Called on Drop Timeout.  See Drop_timer constructor.</span></div>
<div class="line"><a id="l00439" name="l00439"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a862595a7ec5d4bea05ad0e85c52e88ac">  439</a></span><span class="comment"></span>  <a class="code hl_class" href="classflow_1_1Function.html">Function</a>&lt;void (<span class="keywordtype">bool</span> drop_all_packets)&gt; <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a862595a7ec5d4bea05ad0e85c52e88ac">m_timer_fired</a>;</div>
<div class="line"><a id="l00440" name="l00440"></a><span class="lineno">  440</span><span class="comment"></span> </div>
<div class="line"><a id="l00441" name="l00441"></a><span class="lineno">  441</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00442" name="l00442"></a><span class="lineno">  442</span><span class="comment">   * Packet IDs of packets to have been sent over wire and still considered In-flight, ordered from</span></div>
<div class="line"><a id="l00443" name="l00443"></a><span class="lineno">  443</span><span class="comment">   * earliest to latest to have been sent out.  These are packet IDs for which on_packet_in_flight() but not</span></div>
<div class="line"><a id="l00444" name="l00444"></a><span class="lineno">  444</span><span class="comment">   * yet on_packet_no_longer_in_flight() has been called.</span></div>
<div class="line"><a id="l00445" name="l00445"></a><span class="lineno">  445</span><span class="comment">   *</span></div>
<div class="line"><a id="l00446" name="l00446"></a><span class="lineno">  446</span><span class="comment">   * Since the iterator ordering is increasing numerical order (ordered set of `packet_id`s), and `packet_id`s passed to</span></div>
<div class="line"><a id="l00447" name="l00447"></a><span class="lineno">  447</span><span class="comment">   * on_packet_in_flight() must be increasing from call to call, the aforementioned ordering (by time sent) is</span></div>
<div class="line"><a id="l00448" name="l00448"></a><span class="lineno">  448</span><span class="comment">   * expressed via the iterator ordering.  Thus the earliest-sent packet is easily accessible via `begin()`; this is</span></div>
<div class="line"><a id="l00449" name="l00449"></a><span class="lineno">  449</span><span class="comment">   * needed for certain drop-timer situations.</span></div>
<div class="line"><a id="l00450" name="l00450"></a><span class="lineno">  450</span><span class="comment">   *</span></div>
<div class="line"><a id="l00451" name="l00451"></a><span class="lineno">  451</span><span class="comment">   * Logarithmic-time erasure for on_packet_no_longer_in_flight() is also available.</span></div>
<div class="line"><a id="l00452" name="l00452"></a><span class="lineno">  452</span><span class="comment">   */</span></div>
<div class="line"><a id="l00453" name="l00453"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a83bacd0cfe7c6fb6349688012d472f1f">  453</a></span>  std::set&lt;packet_id_t&gt; <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a83bacd0cfe7c6fb6349688012d472f1f">m_flying_packets</a>;</div>
<div class="line"><a id="l00454" name="l00454"></a><span class="lineno">  454</span><span class="comment"></span> </div>
<div class="line"><a id="l00455" name="l00455"></a><span class="lineno">  455</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00456" name="l00456"></a><span class="lineno">  456</span><span class="comment">   * The packet ID of the least recently sent In-flight packet at last</span></div>
<div class="line"><a id="l00457" name="l00457"></a><span class="lineno">  457</span><span class="comment">   * start_contemporaneous_events() call; or 0 if `m_flying_packets.empty()` at the time.</span></div>
<div class="line"><a id="l00458" name="l00458"></a><span class="lineno">  458</span><span class="comment">   */</span></div>
<div class="line"><a id="l00459" name="l00459"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a2ae6617225acb8c4b0798f113c1827d0">  459</a></span>  <a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">packet_id_t</a> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a2ae6617225acb8c4b0798f113c1827d0">m_at_events_start_oldest_flying_packet</a>;</div>
<div class="line"><a id="l00460" name="l00460"></a><span class="lineno">  460</span><span class="comment"></span> </div>
<div class="line"><a id="l00461" name="l00461"></a><span class="lineno">  461</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00462" name="l00462"></a><span class="lineno">  462</span><span class="comment">   * During the time period starting with the last start_contemporaneous_events() call and ending with the subsequent</span></div>
<div class="line"><a id="l00463" name="l00463"></a><span class="lineno">  463</span><span class="comment">   * end_contemporaneous_events() call, if any -- in other words, during the last</span></div>
<div class="line"><a id="l00464" name="l00464"></a><span class="lineno">  464</span><span class="comment">   * contemporary events group, finished or otherwise -- this is the ID of the most-recently-sent packet (highest</span></div>
<div class="line"><a id="l00465" name="l00465"></a><span class="lineno">  465</span><span class="comment">   * packet ID) such that that packet was acknowledged during that time period. 0 if none were acknowledged.</span></div>
<div class="line"><a id="l00466" name="l00466"></a><span class="lineno">  466</span><span class="comment">   */</span></div>
<div class="line"><a id="l00467" name="l00467"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#a0d90b548d2c7062e1ac88b998a2fc1d5">  467</a></span>  <a class="code hl_typedef" href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">packet_id_t</a> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#a0d90b548d2c7062e1ac88b998a2fc1d5">m_during_events_newest_acked_packet</a>;</div>
<div class="line"><a id="l00468" name="l00468"></a><span class="lineno">  468</span><span class="comment"></span> </div>
<div class="line"><a id="l00469" name="l00469"></a><span class="lineno">  469</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00470" name="l00470"></a><span class="lineno">  470</span><span class="comment">   * `true` if and only if the last start_contemporaneous_events() call exists, and either end_contemporaneous_events()</span></div>
<div class="line"><a id="l00471" name="l00471"></a><span class="lineno">  471</span><span class="comment">   * hasn&#39;t been called at all or was called before the former call.</span></div>
<div class="line"><a id="l00472" name="l00472"></a><span class="lineno">  472</span><span class="comment">   */</span></div>
<div class="line"><a id="l00473" name="l00473"></a><span class="lineno"><a class="line" href="classflow_1_1net__flow_1_1Drop__timer.html#addd06c5f17e59cbfd70677831a66bc57">  473</a></span>  <span class="keywordtype">bool</span> <a class="code hl_variable" href="classflow_1_1net__flow_1_1Drop__timer.html#addd06c5f17e59cbfd70677831a66bc57">m_in_events_group</a>;</div>
<div class="line"><a id="l00474" name="l00474"></a><span class="lineno">  474</span>}; <span class="comment">// class Drop_timer</span></div>
<div class="line"><a id="l00475" name="l00475"></a><span class="lineno">  475</span> </div>
<div class="line"><a id="l00476" name="l00476"></a><span class="lineno">  476</span>} <span class="comment">// namespace flow::net_flow</span></div>
<div class="ttc" id="aclassflow_1_1Function_html"><div class="ttname"><a href="classflow_1_1Function.html">flow::Function</a></div><div class="ttdef"><b>Definition:</b> <a href="common_8hpp_source.html#l00512">common.hpp:512</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Log__context_html"><div class="ttname"><a href="classflow_1_1log_1_1Log__context.html">flow::log::Log_context</a></div><div class="ttdoc">Convenience class that simply stores a Logger and/or Component passed into a constructor; and returns...</div><div class="ttdef"><b>Definition:</b> <a href="log_8hpp_source.html#l01609">log.hpp:1610</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Logger_html"><div class="ttname"><a href="classflow_1_1log_1_1Logger.html">flow::log::Logger</a></div><div class="ttdoc">Interface that the user should implement, passing the implementing Logger into logging classes (Flow'...</div><div class="ttdef"><b>Definition:</b> <a href="log_8hpp_source.html#l01280">log.hpp:1284</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html">flow::net_flow::Drop_timer</a></div><div class="ttdoc">Internal net_flow class that maintains the Drop Timer for DATA packet(s) to have been sent out over a...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00145">drop_timer.hpp:152</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a0930c4da4484ffc1f8bcfbc496e5ecd0"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a0930c4da4484ffc1f8bcfbc496e5ecd0">flow::net_flow::Drop_timer::packet_id_t</a></div><div class="ttdeci">Sequence_number::seq_num_t packet_id_t</div><div class="ttdoc">Type to uniquely identify a packet sent over the wire in the socket to which this Drop_timer applies.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00162">drop_timer.hpp:162</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a0d90b548d2c7062e1ac88b998a2fc1d5"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a0d90b548d2c7062e1ac88b998a2fc1d5">flow::net_flow::Drop_timer::m_during_events_newest_acked_packet</a></div><div class="ttdeci">packet_id_t m_during_events_newest_acked_packet</div><div class="ttdoc">During the time period starting with the last start_contemporaneous_events() call and ending with the...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00467">drop_timer.hpp:467</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a21e78b9da6196043e1c05589c46911fa"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a21e78b9da6196043e1c05589c46911fa">flow::net_flow::Drop_timer::m_timer_failure</a></div><div class="ttdeci">Function&lt; void(const Error_code &amp;err_code)&gt; m_timer_failure</div><div class="ttdoc">Called on error. See Drop_timer constructor.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00436">drop_timer.hpp:436</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a2ae6617225acb8c4b0798f113c1827d0"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a2ae6617225acb8c4b0798f113c1827d0">flow::net_flow::Drop_timer::m_at_events_start_oldest_flying_packet</a></div><div class="ttdeci">packet_id_t m_at_events_start_oldest_flying_packet</div><div class="ttdoc">The packet ID of the least recently sent In-flight packet at last start_contemporaneous_events() call...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00459">drop_timer.hpp:459</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a40029643f0a6c7a2a6b20499ca4c5a67"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a40029643f0a6c7a2a6b20499ca4c5a67">flow::net_flow::Drop_timer::timer_failure</a></div><div class="ttdeci">void timer_failure(Ptr prevent_destruction, const Error_code &amp;err_code)</div><div class="ttdoc">Called by boost.asio after we post it, in the event of some timer error.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00556">drop_timer.cpp:556</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a45d4cf2dfecc2cd5c35f452cd7c8d05d"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a45d4cf2dfecc2cd5c35f452cd7c8d05d">flow::net_flow::Drop_timer::end_contemporaneous_events</a></div><div class="ttdeci">void end_contemporaneous_events()</div><div class="ttdoc">Finishes the group started by start start_contemporaneous_events().</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00118">drop_timer.cpp:118</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a477fd69a6978cc228b8e80611aa234ba"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a477fd69a6978cc228b8e80611aa234ba">flow::net_flow::Drop_timer::on_ack</a></div><div class="ttdeci">void on_ack(packet_id_t packet_id)</div><div class="ttdoc">Indicates that a packet for which on_packet_in_flight() was called has just been validly acked.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00072">drop_timer.cpp:72</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a4a5f0bbb91232e17e258722e4dfa237b"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a4a5f0bbb91232e17e258722e4dfa237b">flow::net_flow::Drop_timer::start_timer</a></div><div class="ttdeci">void start_timer()</div><div class="ttdoc">Starts a new wait on the timer, so that is it asynchronously triggered according to the current DTO v...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00347">drop_timer.cpp:347</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a5d1fff72b5c044cba0651de0508553e0"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a5d1fff72b5c044cba0651de0508553e0">flow::net_flow::Drop_timer::on_packet_no_longer_in_flight</a></div><div class="ttdeci">void on_packet_no_longer_in_flight(packet_id_t packet_id)</div><div class="ttdoc">Indicates that a packet for which on_packet_in_flight() was called is now no longer considered In-fli...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00092">drop_timer.cpp:92</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a60e386c24490bd5880e9e8700e59ca6d"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a60e386c24490bd5880e9e8700e59ca6d">flow::net_flow::Drop_timer::~Drop_timer</a></div><div class="ttdeci">~Drop_timer()</div><div class="ttdoc">Destructor.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00316">drop_timer.cpp:316</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a64def367e38954d8a392cdf92fcc8f24"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a64def367e38954d8a392cdf92fcc8f24">flow::net_flow::Drop_timer::create_drop_timer</a></div><div class="ttdeci">static Ptr create_drop_timer(log::Logger *logger_ptr, util::Task_engine *node_task_engine, Fine_duration *sock_drop_timeout, Peer_socket::Const_ptr &amp;&amp;sock, const Function&lt; void(const Error_code &amp;err_code)&gt; &amp;timer_failure, const Function&lt; void(bool drop_all_packets)&gt; &amp;timer_fired)</div><div class="ttdoc">Constructs Drop_timer and returns a ref-counted pointer wrapping it.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00027">drop_timer.cpp:28</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a7ab957ddc07d6289d1b42d6686173533"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a7ab957ddc07d6289d1b42d6686173533">flow::net_flow::Drop_timer::m_sock</a></div><div class="ttdeci">const Peer_socket::Const_ptr m_sock</div><div class="ttdoc">The containing Peer_socket (note that this is read-only access).</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00392">drop_timer.hpp:392</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a83bacd0cfe7c6fb6349688012d472f1f"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a83bacd0cfe7c6fb6349688012d472f1f">flow::net_flow::Drop_timer::m_flying_packets</a></div><div class="ttdeci">std::set&lt; packet_id_t &gt; m_flying_packets</div><div class="ttdoc">Packet IDs of packets to have been sent over wire and still considered In-flight, ordered from earlie...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00453">drop_timer.hpp:453</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a862595a7ec5d4bea05ad0e85c52e88ac"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a862595a7ec5d4bea05ad0e85c52e88ac">flow::net_flow::Drop_timer::m_timer_fired</a></div><div class="ttdeci">Function&lt; void(bool drop_all_packets)&gt; m_timer_fired</div><div class="ttdoc">Called on Drop Timeout. See Drop_timer constructor.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00439">drop_timer.hpp:439</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a9528326a35b021bb859bed948ae3d7a4"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a9528326a35b021bb859bed948ae3d7a4">flow::net_flow::Drop_timer::m_timer_running</a></div><div class="ttdeci">bool m_timer_running</div><div class="ttdoc">Is there an active (non-obsolete, not-canceled) asynchronous wait in progress on m_timer?...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00408">drop_timer.hpp:408</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a9c94b0191a80afb98b6da4a2d0b47a46"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a9c94b0191a80afb98b6da4a2d0b47a46">flow::net_flow::Drop_timer::Drop_timer</a></div><div class="ttdeci">Drop_timer(log::Logger *logger, util::Task_engine *node_task_engine, Fine_duration *sock_drop_timeout, Peer_socket::Const_ptr &amp;&amp;sock, const Function&lt; void(const Error_code &amp;err_code)&gt; &amp;timer_failure, const Function&lt; void(bool drop_all_packets)&gt; &amp;timer_fired)</div><div class="ttdoc">Constructs Drop_timer as described in the factory constructor create_drop_timer().</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00293">drop_timer.cpp:293</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_a9de653d7372110ffd176ef34e916a7dd"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#a9de653d7372110ffd176ef34e916a7dd">flow::net_flow::Drop_timer::m_done</a></div><div class="ttdeci">bool m_done</div><div class="ttdoc">true if and only if done() has been called. Starts at false, can only change to true.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00433">drop_timer.hpp:433</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_aa9af1ac250a1a40f3c8df5878e55b98c"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#aa9af1ac250a1a40f3c8df5878e55b98c">flow::net_flow::Drop_timer::m_current_wait_id</a></div><div class="ttdeci">timer_wait_id_t m_current_wait_id</div><div class="ttdoc">Unique (within this object) identifier of the last start_timer() call.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00430">drop_timer.hpp:430</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_aaf4f0fce1d41e16309beca40a126e2f0"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#aaf4f0fce1d41e16309beca40a126e2f0">flow::net_flow::Drop_timer::handle_timer_firing</a></div><div class="ttdeci">void handle_timer_firing(Ptr prevent_destruction, timer_wait_id_t wait_id, const Error_code &amp;sys_err_code)</div><div class="ttdoc">Called by boost.asio when the Drop Timer fires; disables timer and calls an outside action callback (...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00462">drop_timer.cpp:462</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_ab6b96e0200579afdee1bf1ce58ab5ad2"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#ab6b96e0200579afdee1bf1ce58ab5ad2">flow::net_flow::Drop_timer::done</a></div><div class="ttdeci">void done()</div><div class="ttdoc">Causes the Drop_timer to guarantee none of the action callbacks provided at construction will be call...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00321">drop_timer.cpp:321</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_abf88c319884e5c5eb1b8f63c646e90ad"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#abf88c319884e5c5eb1b8f63c646e90ad">flow::net_flow::Drop_timer::start_contemporaneous_events</a></div><div class="ttdeci">void start_contemporaneous_events()</div><div class="ttdoc">Indicates the start of a series of zero or more contemporary on_*() event calls, to be marked as fini...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00041">drop_timer.cpp:41</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_ac3cfab1594111b3c3254eebc84591908"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#ac3cfab1594111b3c3254eebc84591908">flow::net_flow::Drop_timer::m_node_task_engine</a></div><div class="ttdeci">util::Task_engine &amp; m_node_task_engine</div><div class="ttdoc">Node::m_task_engine of the containing Node. Used to schedule timer events.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00376">drop_timer.hpp:376</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_ac5a7ab3108a915999e95ccf705006ccd"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#ac5a7ab3108a915999e95ccf705006ccd">flow::net_flow::Drop_timer::on_no_packets_in_flight_any_longer</a></div><div class="ttdeci">void on_no_packets_in_flight_any_longer()</div><div class="ttdoc">Equivalent to on_packet_no_longer_in_flight(P), for all P currently In-flight as registered by on_pac...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00105">drop_timer.cpp:105</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_ad5dfc3cd2f8e5e4d28c49e28ee5c221f"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#ad5dfc3cd2f8e5e4d28c49e28ee5c221f">flow::net_flow::Drop_timer::m_timer</a></div><div class="ttdeci">util::Timer m_timer</div><div class="ttdoc">The Drop Timer itself.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00398">drop_timer.hpp:398</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_ad655d5461aa5a6bf9a80d28e4a4fdd77"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#ad655d5461aa5a6bf9a80d28e4a4fdd77">flow::net_flow::Drop_timer::disable_timer</a></div><div class="ttdeci">void disable_timer()</div><div class="ttdoc">Invalidates the running asynchronous wait on m_timer. Pre-condition: m_timer_running.</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00437">drop_timer.cpp:437</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_ad9db6f435dfc65b7bd4b539467f1c3ec"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db6f435dfc65b7bd4b539467f1c3ec">flow::net_flow::Drop_timer::timer_wait_id_t</a></div><div class="ttdeci">uint64_t timer_wait_id_t</div><div class="ttdoc">The counter type used to distinguish a given start_timer() call from any other such call (for this ob...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00297">drop_timer.hpp:297</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_ad9db83f50aec60604de55d01e15ea403"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#ad9db83f50aec60604de55d01e15ea403">flow::net_flow::Drop_timer::m_sock_drop_timeout</a></div><div class="ttdeci">Fine_duration &amp; m_sock_drop_timeout</div><div class="ttdoc">Reference to the containing Peer_socket's Peer_socket::m_snd_drop_timeout data member (= DTO,...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00385">drop_timer.hpp:385</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_addd06c5f17e59cbfd70677831a66bc57"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#addd06c5f17e59cbfd70677831a66bc57">flow::net_flow::Drop_timer::m_in_events_group</a></div><div class="ttdeci">bool m_in_events_group</div><div class="ttdoc">true if and only if the last start_contemporaneous_events() call exists, and either end_contemporaneo...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8hpp_source.html#l00473">drop_timer.hpp:473</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Drop__timer_html_afc1bf0978b04d454f5aa228a44550565"><div class="ttname"><a href="classflow_1_1net__flow_1_1Drop__timer.html#afc1bf0978b04d454f5aa228a44550565">flow::net_flow::Drop_timer::on_packet_in_flight</a></div><div class="ttdeci">void on_packet_in_flight(packet_id_t packet_id)</div><div class="ttdoc">Indicates that a packet identified by the given unique ID has just been sent over the wire (the low-l...</div><div class="ttdef"><b>Definition:</b> <a href="drop__timer_8cpp_source.html#l00052">drop_timer.cpp:52</a></div></div>
<div class="ttc" id="aclassflow_1_1net__flow_1_1Sequence__number_html_ab307e12c0cf8cefbe7fb1ec8588af2a8"><div class="ttname"><a href="classflow_1_1net__flow_1_1Sequence__number.html#ab307e12c0cf8cefbe7fb1ec8588af2a8">flow::net_flow::Sequence_number::seq_num_t</a></div><div class="ttdeci">uint64_t seq_num_t</div><div class="ttdoc">Raw sequence number type.</div><div class="ttdef"><b>Definition:</b> <a href="seq__num_8hpp_source.html#l00138">seq_num.hpp:138</a></div></div>
<div class="ttc" id="aclassflow_1_1util_1_1Shared__ptr__alias__holder_html"><div class="ttname"><a href="classflow_1_1util_1_1Shared__ptr__alias__holder.html">flow::util::Shared_ptr_alias_holder</a></div><div class="ttdoc">Convenience class template that endows the given subclass T with nested aliases Ptr and Const_ptr ali...</div><div class="ttdef"><b>Definition:</b> <a href="shared__ptr__alias__holder_8hpp_source.html#l00119">shared_ptr_alias_holder.hpp:120</a></div></div>
<div class="ttc" id="aclassflow_1_1util_1_1Shared__ptr__alias__holder_html_aa4f1af88393042e60159a3a67f0accbc"><div class="ttname"><a href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aa4f1af88393042e60159a3a67f0accbc">flow::util::Shared_ptr_alias_holder&lt; boost::shared_ptr&lt; Drop_timer &gt; &gt;::Ptr</a></div><div class="ttdeci">boost::shared_ptr&lt; Drop_timer &gt; Ptr</div><div class="ttdoc">Short-hand for ref-counted pointer to mutable values of type Target_type::element_type (a-la T*).</div><div class="ttdef"><b>Definition:</b> <a href="shared__ptr__alias__holder_8hpp_source.html#l00125">shared_ptr_alias_holder.hpp:125</a></div></div>
<div class="ttc" id="aclassflow_1_1util_1_1Shared__ptr__alias__holder_html_aef7998db71c60eeb5d1e3d1a97c14886"><div class="ttname"><a href="classflow_1_1util_1_1Shared__ptr__alias__holder.html#aef7998db71c60eeb5d1e3d1a97c14886">flow::util::Shared_ptr_alias_holder&lt; boost::shared_ptr&lt; Peer_socket &gt; &gt;::Const_ptr</a></div><div class="ttdeci">Const_target_ptr Const_ptr</div><div class="ttdoc">Short-hand for ref-counted pointer to immutable values of type Target_type::element_type (a-la T cons...</div><div class="ttdef"><b>Definition:</b> <a href="shared__ptr__alias__holder_8hpp_source.html#l00127">shared_ptr_alias_holder.hpp:127</a></div></div>
<div class="ttc" id="adetail_2net__flow__fwd_8hpp_html"><div class="ttname"><a href="detail_2net__flow__fwd_8hpp.html">net_flow_fwd.hpp</a></div></div>
<div class="ttc" id="anamespaceflow_1_1net__flow_html"><div class="ttname"><a href="namespaceflow_1_1net__flow.html">flow::net_flow</a></div><div class="ttdoc">Flow module containing the API and implementation of the Flow network protocol, a TCP-inspired stream...</div><div class="ttdef"><b>Definition:</b> <a href="asio_2node_8cpp_source.html#l00024">node.cpp:25</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_ac3e89a8a271b0ddc76ac2a0ce488dea4"><div class="ttname"><a href="namespaceflow_1_1util.html#ac3e89a8a271b0ddc76ac2a0ce488dea4">flow::util::Task_engine</a></div><div class="ttdeci">boost::asio::io_context Task_engine</div><div class="ttdoc">Short-hand for boost.asio event service, the central class of boost.asio.</div><div class="ttdef"><b>Definition:</b> <a href="util__fwd_8hpp_source.html#l00135">util_fwd.hpp:135</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_ae7416d64d2989051104bb396e28e15e6"><div class="ttname"><a href="namespaceflow_1_1util.html#ae7416d64d2989051104bb396e28e15e6">flow::util::Timer</a></div><div class="ttdeci">boost::asio::basic_waitable_timer&lt; Fine_clock &gt; Timer</div><div class="ttdoc">boost.asio timer.</div><div class="ttdef"><b>Definition:</b> <a href="util__fwd_8hpp_source.html#l00202">util_fwd.hpp:202</a></div></div>
<div class="ttc" id="anamespaceflow_html_a29eaaa9d0fac4ce87d8b969222dbed09"><div class="ttname"><a href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">flow::Error_code</a></div><div class="ttdeci">boost::system::error_code Error_code</div><div class="ttdoc">Short-hand for a boost.system error code (which basically encapsulates an integer/enum error code and...</div><div class="ttdef"><b>Definition:</b> <a href="common_8hpp_source.html#l00508">common.hpp:508</a></div></div>
<div class="ttc" id="anamespaceflow_html_a48799f1263cdeedec125be51a3db2b79"><div class="ttname"><a href="namespaceflow.html#a48799f1263cdeedec125be51a3db2b79">flow::Fine_duration</a></div><div class="ttdeci">Fine_clock::duration Fine_duration</div><div class="ttdoc">A high-res time duration as computed from two Fine_time_pts.</div><div class="ttdef"><b>Definition:</b> <a href="common_8hpp_source.html#l00416">common.hpp:416</a></div></div>
<div class="ttc" id="apeer__socket_8hpp_html"><div class="ttname"><a href="peer__socket_8hpp.html">peer_socket.hpp</a></div></div>
<div class="ttc" id="ashared__ptr__alias__holder_8hpp_html"><div class="ttname"><a href="shared__ptr__alias__holder_8hpp.html">shared_ptr_alias_holder.hpp</a></div></div>
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